Methionine synthesis by extracts of Salmonella typhimurium.
1. Following the genetic studies by Smith (1961) and Smith & Childs (1963) with methionine auxotrophs of Salmonella typhimurium, methionine formation from homocysteine has been investigated with cell-free extracts of this organism. 2. As found with Escherichia coli (Woods, Foster & Guest, 1964), methyl groups are formed by an N(5)N(10)-methylenetetrahydrofolate reductase. They are then transferred to homocysteine by either a simple N(5)-methyltetrahydropteroyl-triglutamate-homocysteine methyltransferase or alternatively a cobalamin-dependent N(5)-methyltetrahydrofolate-homocysteine methyltransferase. 3. S. typhimurium differs from E. coli in being able to synthesize significant amounts of cobalamin.
D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000478:Alkylation; D006710:Homocysteine / Q000378:metabolism*; D066298:In Vitro Techniques; D008715:Methionine / Q000096:biosynthesis*; D008967:Molecular Biology; D012486:Salmonella typhimurium / Q000201:enzymology / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D014805:Vitamin B 12 / Q000378:metabolism
D006710:Homocysteine; D012694:Serine; D008715:Methionine; D000429:Alcohol Oxidoreductases; D014805:Vitamin B 12